US4284891A - Gamma camera - Google Patents

Gamma camera Download PDF

Info

Publication number
US4284891A
US4284891A US06/099,456 US9945679A US4284891A US 4284891 A US4284891 A US 4284891A US 9945679 A US9945679 A US 9945679A US 4284891 A US4284891 A US 4284891A
Authority
US
United States
Prior art keywords
scintillation crystal
optical conductor
gamma camera
optical
scintillation
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US06/099,456
Inventor
Jean Pergrale
Michel Jatteau
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
US Philips Corp
Original Assignee
US Philips Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by US Philips Corp filed Critical US Philips Corp
Application granted granted Critical
Publication of US4284891A publication Critical patent/US4284891A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01T—MEASUREMENT OF NUCLEAR OR X-RADIATION
    • G01T1/00—Measuring X-radiation, gamma radiation, corpuscular radiation, or cosmic radiation
    • G01T1/16—Measuring radiation intensity
    • G01T1/161—Applications in the field of nuclear medicine, e.g. in vivo counting
    • G01T1/164—Scintigraphy
    • G01T1/1641—Static instruments for imaging the distribution of radioactivity in one or two dimensions using one or several scintillating elements; Radio-isotope cameras
    • G01T1/1642—Static instruments for imaging the distribution of radioactivity in one or two dimensions using one or several scintillating elements; Radio-isotope cameras using a scintillation crystal and position sensing photodetector arrays, e.g. ANGER cameras

Definitions

  • the invention relates to a gamma camera which comprises a scintillation crystal, an optical conductor which is arranged against the scintillation crystal, a network of photomultiplier tubes whose entrance faces are situated opposite the optical conductor, the transverse dimension of the optical conductor being larger than that of the scintillation crystal, the assembly formed by the optical conductor and the scintillation crystal being accommodated in a metal housing which is open at the side of the photomultipliers, the entrance surfaces of peripheral photomultipliers projecting beyond the surface of the scintillation crystal, the useful field of the camera being defined by an aperture which is arranged at the side of the scintillation crystal.
  • a gamma camera of this kind is known from U.S. Pat. No. 3,011,057 and comprises an optical block with a disc-shaped scintillation crystal which is arranged against a disc-shaped optical conductor on which a network of photomultipliers is arranged for detecting scintaillations caused by gamma radiation incident in the scintillation crystal.
  • the useful field of such a gamma camera is limited by an aperture arranged in front of the scintillation crystal.
  • Electronic circuits combine the output signals of the photomultipliers in order to assign position coordinates to the detected signals, so that the position of the scintillation occuring in the crystal is defined.
  • One of the causes of the non-linear character of the camera is also formed by the "edge effect" of the optical block, because the optical properties of the surface of the block partly control the manner in which the light is distributed among the photomultipliers.
  • the photomultipliers situated nearest to the edge are more susceptible to this effect.
  • French Pat. Specification No. 2,219,424 proposes a correction of these errors which utilizes an electronic circuit which readjusts, at a later stage, the signals detected by the photomultipliers of the central portion of the network.
  • the signal amplifier circuits become extremely complex and the level of the signals of the central photomultipliers is selectively reduced.
  • the improvement in linearity is accompanied by a loss of spatial and energetic resolution of the camera.
  • French Pat. Specification No. 2,168,250 proposes an optical correction method utilizing light-diffusing elements which are comparatively opaque and which are arranged between the scintillation crystal and the optical conductor, underneath each of said photomultiplier tubes in the central zone of the camera.
  • French Pat. Specification No. 2,219,423 describes the use of conical elements which transmit half of the scintillation light and reflect this light in different manners, depending on the angle of incidence, said elements being accomodated in the optical conductors on the right side of the centrally situated photomultiplier tubes.
  • the invention has for its object to realize a good and readily achievable compromise between on the one hand the spatial linearity and uniformity and on the other hand the spatial and energetic resolution, while at the same time the edge effect is reduced.
  • a gamma camera of the kind set forth is characterized in that the peripheral part of the surface of the optical conductor is provided, at least at the side of the scintillation crystal, with a diffusive light reflector, the reflection and optical diffusion properties of which are combined in dependence of the wavelength of the scintillation light so that the signal/distance curves of all photomultipliers coincide for scintillations occuring within the useful field of the camera.
  • the visual aspect of the diffusive reflector can be strongly aried in colour, that is to say in a wavelength-dependent manner.
  • the diffusive reflector is arranged on a part of the circumference of the surface of the optical conductor at the side of the scintillator and/or on at least a part of the side edge of said optical conductor.
  • the diffusive reflector is formed by three surfaces having composite optical diffusion properties which are situated very near to each other and which are formed on the one hand by at least a part of the internal surface of a housing for the scintillator and the optical conductor, the apparent colour of said surface being metallic grey, and on the other hand by at least a part of the surface of the optical conductor which is situated opposite said housing surface, and which has been roughened.
  • FIG. 1 shows a preferred embodiment of a gamma camera in accordance with the invention, viewed from the side of the photomultiplier tubes,
  • FIG. 2 shows a gamma camera with facilities in accordance with the invention which are arranged on the detection side, viewed in the plane AB of FIG. 1,
  • FIG. 3a shows the signal/distance curves of the detecting photomultipliers of a known gamma camera
  • FIG. 3b shows the corresponding signal/distance curves of a gamma camera in accordance with the invention.
  • FIGS. 1 and 2 show, by way of example, the circumference 10 of a scintillator and the circumference 11 of an optical conductor forming part of a gamma camera having a circular cross-section; however, this cross-section may also be, for example, rectangular.
  • Entrance windows 12 of photomultipliers together form a network and are situated opposite a scintillation crystal 21 on an optical conductor 22.
  • the photomultipliers form, for example, a hexagonal configuration around a central photomultiplier.
  • a photomultiplier 13a is the central photomultiplier of the network.
  • Photomultipliers 13b, 13c, 13d are arranged along a central cross-sectional line AB.
  • two photomultipliers which are symmetrical with respect to the photomultiplier 13a and which are arranged along the cross-section a line AB are denoted by the same reference numeral in the Figures.
  • FIG. 2 is a cross-sectional view of the entrance of the camera, taken along the line AB in FIG. 1.
  • the scintillator 21 and the optical conductor 22 are more clearly shown.
  • the photomultipliers 13a, 13b, 13c, 13d are arranged on the optical conductor 22.
  • the edge 10 of the scintillator 21 coincides approximately with centres 24 of the photomultipliers 13d, whilst the edge 11 of the optical conductor coincides with the outer boundary thereof.
  • An aperture 20 which is arranged in front of the scintillator defines a useful field of the gamma camera.
  • FIG. 3a shows a series of response curves of photomultiplier tubes arranged along the line AB for the case where a point-like gamma radiation source is displaced along this line.
  • a signal w originating from the photomultiplier, is plotted along the vertical axis, whilst the distance d between the gamma radiation source and the axis of the relevant photomultiplier is plotted along the horizontal axis.
  • the distance d between the axis 28 and the source S is the distance d between the axis 28 and the source S.
  • the curves 31,32, 33 and 34 for the relevant photomultipliers 13a, 13b, 13c and 13d do not coincide, but are situated at an increasingly lower level for the photomultipliers situated nearer to the edge.
  • the surface 26 of the optical conductor comprises a diffusive reflector having adapted absorption and diffusion properties, depending on the wavelength of the scintillation light.
  • An adaptation of the diffusive reflector is found in the colour thereof, that is to say a wavelength-dependent degree of reflection and transmission.
  • the diffusive reflector is formed as shown in FIG. 2.
  • the assembly formed by the scintillator 21 and the optical conductor 22 is arranged in known manner in a housing which is open at the side of the photomultipliers.
  • Surfaces 30 and 35 which are situated opposite the optical conductor 22 have a grey colour and are roughened.
  • the surface 26 of the optical conductor which is situated opposite the surface 30 and a surface 36 thereof which is situated opposite the surface 35 have been roughened.
  • the grey, diffusive reflector used in accordance with the invention is formed by cooperation of the surfaces 30 and 35 with the surfaces 26 and 36 which are situated at a very short distance from each other and whose reflection and optical diffusion properties are combined in respect of their colour and surface condition.

Abstract

The peripheral part of the optical block of a gamma camera, which is formed by the scintillation crystal and the optical conductor, is provided with a diffusive light reflector, the reflection and optical diffusion properties of which are combined in relation to the wavelength of the scintillation light so that signal/distance curves for each of the photomultipliers used are substantially coincident within the useful field of the camera. This improvement results in a suitable compromise between on the one hand linearity and spatial uniformity and on the other hand spatial and energetic resolution of the gamma camera.

Description

The invention relates to a gamma camera which comprises a scintillation crystal, an optical conductor which is arranged against the scintillation crystal, a network of photomultiplier tubes whose entrance faces are situated opposite the optical conductor, the transverse dimension of the optical conductor being larger than that of the scintillation crystal, the assembly formed by the optical conductor and the scintillation crystal being accommodated in a metal housing which is open at the side of the photomultipliers, the entrance surfaces of peripheral photomultipliers projecting beyond the surface of the scintillation crystal, the useful field of the camera being defined by an aperture which is arranged at the side of the scintillation crystal.
A gamma camera of this kind is known from U.S. Pat. No. 3,011,057 and comprises an optical block with a disc-shaped scintillation crystal which is arranged against a disc-shaped optical conductor on which a network of photomultipliers is arranged for detecting scintaillations caused by gamma radiation incident in the scintillation crystal. The useful field of such a gamma camera is limited by an aperture arranged in front of the scintillation crystal. Electronic circuits combine the output signals of the photomultipliers in order to assign position coordinates to the detected signals, so that the position of the scintillation occuring in the crystal is defined. Thanks to the use of a collimator, only quanta which are incident approximately at right angles are admitted, so that the source causing said scintillations is also localized. Signals thus extracted can be displayed as an image on a display screen. This spatial display is disturbed by errors in linearity and uniformity. The existence of such errors can be demonstrated by irradiating the scintillation crystal with a flux of gamma rays having a spatially uniform distribution. Points obtained on the screen of the camera then exhibit a non-uniform spatial distribution. A substantially higher density of points occurs in the areas which correspond to positions which are situated centrally opposite entrance windows of notably centrally situated photomultipliers tubes. This can be explained as follows: when a scintillation occurs in a given point of the scintillation crystal near the axis of one of the central photomultiplier tubes, the point displayed on the screen has been shifted to a position which is situated nearer to the axis of the tube than the actual position of the scintillation. This shifting of the scintillation towards the axis of the photomultiplier is better visible in the central portion of the screen that at the circumference thereof.
One of the causes of the non-linear character of the camera is also formed by the "edge effect" of the optical block, because the optical properties of the surface of the block partly control the manner in which the light is distributed among the photomultipliers. The photomultipliers situated nearest to the edge are more susceptible to this effect.
French Pat. Specification No. 2,219,424 proposes a correction of these errors which utilizes an electronic circuit which readjusts, at a later stage, the signals detected by the photomultipliers of the central portion of the network. As a result, the signal amplifier circuits become extremely complex and the level of the signals of the central photomultipliers is selectively reduced. Moreover, the improvement in linearity is accompanied by a loss of spatial and energetic resolution of the camera.
French Pat. Specification No. 2,168,250 proposes an optical correction method utilizing light-diffusing elements which are comparatively opaque and which are arranged between the scintillation crystal and the optical conductor, underneath each of said photomultiplier tubes in the central zone of the camera. Similarly, French Pat. Specification No. 2,219,423 describes the use of conical elements which transmit half of the scintillation light and reflect this light in different manners, depending on the angle of incidence, said elements being accomodated in the optical conductors on the right side of the centrally situated photomultiplier tubes. These optical correction methods make the construction of the optical block of the camera more complex and also have the drawback that the improved linearity of the camera is obtained at the expense of other properties such as the spatial and energetic resolution.
The invention has for its object to realize a good and readily achievable compromise between on the one hand the spatial linearity and uniformity and on the other hand the spatial and energetic resolution, while at the same time the edge effect is reduced.
This object in accordance with the invention is realized in that a gamma camera of the kind set forth is characterized in that the peripheral part of the surface of the optical conductor is provided, at least at the side of the scintillation crystal, with a diffusive light reflector, the reflection and optical diffusion properties of which are combined in dependence of the wavelength of the scintillation light so that the signal/distance curves of all photomultipliers coincide for scintillations occuring within the useful field of the camera.
Due to the comparatively narrow spectrum of the scintillation light, the visual aspect of the diffusive reflector can be strongly aried in colour, that is to say in a wavelength-dependent manner.
In a general embodiment in accordance with the invention, the diffusive reflector is arranged on a part of the circumference of the surface of the optical conductor at the side of the scintillator and/or on at least a part of the side edge of said optical conductor.
In a preferred embodiment in accordance with the invention, the diffusive reflector is formed by three surfaces having composite optical diffusion properties which are situated very near to each other and which are formed on the one hand by at least a part of the internal surface of a housing for the scintillator and the optical conductor, the apparent colour of said surface being metallic grey, and on the other hand by at least a part of the surface of the optical conductor which is situated opposite said housing surface, and which has been roughened.
The invention will be described in detail hereinafter with reference to the accompanying diagrammatic drawing.
FIG. 1 shows a preferred embodiment of a gamma camera in accordance with the invention, viewed from the side of the photomultiplier tubes,
FIG. 2 shows a gamma camera with facilities in accordance with the invention which are arranged on the detection side, viewed in the plane AB of FIG. 1,
FIG. 3a shows the signal/distance curves of the detecting photomultipliers of a known gamma camera, and
FIG. 3b shows the corresponding signal/distance curves of a gamma camera in accordance with the invention.
FIGS. 1 and 2 show, by way of example, the circumference 10 of a scintillator and the circumference 11 of an optical conductor forming part of a gamma camera having a circular cross-section; however, this cross-section may also be, for example, rectangular. Entrance windows 12 of photomultipliers together form a network and are situated opposite a scintillation crystal 21 on an optical conductor 22. The photomultipliers form, for example, a hexagonal configuration around a central photomultiplier. A photomultiplier 13a is the central photomultiplier of the network. Photomultipliers 13b, 13c, 13d are arranged along a central cross-sectional line AB. For the sake of clarity, two photomultipliers which are symmetrical with respect to the photomultiplier 13a and which are arranged along the cross-section a line AB are denoted by the same reference numeral in the Figures.
FIG. 2, is a cross-sectional view of the entrance of the camera, taken along the line AB in FIG. 1. The scintillator 21 and the optical conductor 22 are more clearly shown. The photomultipliers 13a, 13b, 13c, 13d are arranged on the optical conductor 22. Customarily, the edge 10 of the scintillator 21 coincides approximately with centres 24 of the photomultipliers 13d, whilst the edge 11 of the optical conductor coincides with the outer boundary thereof. An aperture 20 which is arranged in front of the scintillator defines a useful field of the gamma camera.
FIG. 3a shows a series of response curves of photomultiplier tubes arranged along the line AB for the case where a point-like gamma radiation source is displaced along this line. A signal w, originating from the photomultiplier, is plotted along the vertical axis, whilst the distance d between the gamma radiation source and the axis of the relevant photomultiplier is plotted along the horizontal axis. For the photomultiplier 13c, this is the distance d between the axis 28 and the source S. In conformity with the already described deviations, the curves 31,32, 33 and 34 for the relevant photomultipliers 13a, 13b, 13c and 13d do not coincide, but are situated at an increasingly lower level for the photomultipliers situated nearer to the edge.
In accordance with the invention, an attractive compromise is realized between on the one hand the spatial linearity and uniformity of the gamma camera and on the other hand the spatial and energetic resolution of the camera when the response curves coincide better in the manner shown in FIG. 3b. Both cases are limited to a useful field as defined by the aperture 20.
In order to realize the at least substantially coincident curves, the surface 26 of the optical conductor comprises a diffusive reflector having adapted absorption and diffusion properties, depending on the wavelength of the scintillation light. An adaptation of the diffusive reflector is found in the colour thereof, that is to say a wavelength-dependent degree of reflection and transmission.
In a preferred embodiment in accordance with the invention, the diffusive reflector is formed as shown in FIG. 2. The assembly formed by the scintillator 21 and the optical conductor 22 is arranged in known manner in a housing which is open at the side of the photomultipliers. Surfaces 30 and 35 which are situated opposite the optical conductor 22 have a grey colour and are roughened. The surface 26 of the optical conductor which is situated opposite the surface 30 and a surface 36 thereof which is situated opposite the surface 35 have been roughened. The grey, diffusive reflector used in accordance with the invention is formed by cooperation of the surfaces 30 and 35 with the surfaces 26 and 36 which are situated at a very short distance from each other and whose reflection and optical diffusion properties are combined in respect of their colour and surface condition.
It will be clear that the invention, which has been described only with reference to the most commonly used circular shape of the cross-section of the optical block, also relates to a gamma camera whose optical block has a polygonal cross-section and which is, for example, rectangular or square.

Claims (3)

What is claimed is:
1. In a gamma camera which comprises:
a scintillation crystal having a first side and an opposite second side; an optical conductor having a first side disposed against the second side of the scintillation crystal and a second opposite side, a transverse dimension of the optical conductor being larger than a transverse dimension of the scintillation crystal so that a portion of the surface of the optical conductor extends beyond the periphery of the scintillation crystal; a network of photomultiplier tubes including peripheral photomultipliers having entrance faces situated adjacent the second side of the optical conductor, the entrance faces of the peripheral photomultiplier tubes projecting beyond the periphery of the scintillation crystal; aperture means for defining the useful field of the gamma camera disposed adjacent the first side of the scintillation crystal; and a metal housing which surrounds the optical conductor and the scintillation crystal; the improvement comprising:
diffuse light reflector means provided at least on the portion of the surface of the optical conductor which extends beyond the periphery of the scintillation crystal, the reflection and optical diffusing properties of the reflector being a function of the wavelength of the scintillation light, for compensating the signal/distance curves of the photomultiplier tubes so that the signal/distance curves for all photomultiplier tubes in the network substantially coincide for all scintillations occurring within the useful field of the gamma camera.
2. A gamma camera as claimed in claim 1 wherein the optical conductor, the scintillation crystal and the diffuse light reflector means are circular and are disposed along a common axis.
3. A gamma camera as claimed in claim 1 or 2 wherein the diffuse reflector means comprise a roughened area on the surface of the optical conductor and an adjacent inner surface of the housing, the apparent color of the adjacent surface of the housing being metallic gray, the roughened surface and the adjacent surface of the housing being sufficiently close together so that the composite optical properties thereof provide a diffuse light reflector.
US06/099,456 1978-12-05 1979-12-03 Gamma camera Expired - Lifetime US4284891A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR7834169 1978-12-05
FR7834169A FR2443741A1 (en) 1978-12-05 1978-12-05 IMPROVEMENT WITH THE ANGER SCINTILLATION CAMERA

Publications (1)

Publication Number Publication Date
US4284891A true US4284891A (en) 1981-08-18

Family

ID=9215684

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/099,456 Expired - Lifetime US4284891A (en) 1978-12-05 1979-12-03 Gamma camera

Country Status (6)

Country Link
US (1) US4284891A (en)
EP (1) EP0011902B1 (en)
JP (2) JPS5578268A (en)
CA (1) CA1134063A (en)
DE (1) DE2967025D1 (en)
FR (1) FR2443741A1 (en)

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4492869A (en) * 1980-10-22 1985-01-08 Hitachi Medical Corporation Radiation detector
US4817123A (en) * 1984-09-21 1989-03-28 Picker International Digital radiography detector resolution improvement
US5229613A (en) * 1991-09-06 1993-07-20 Horiba Instruments, Incorporated Extended lifetime scintillation camera plate assembly
WO1994029746A1 (en) * 1993-06-14 1994-12-22 Sloan-Kettering Institute For Cancer Research Radiation imaging device having an enlarged uniform field of view
US5442181A (en) * 1991-10-03 1995-08-15 Kabushiki Kaisha Toshiba Radiation detector and its manufacturing method
US5442179A (en) * 1992-09-21 1995-08-15 Hamamatsu Photonics, K.K. Photomultiplier assembly and gamma camera head
US5550378A (en) * 1993-04-05 1996-08-27 Cardiac Mariners, Incorporated X-ray detector
US5763887A (en) * 1995-08-04 1998-06-09 Adac Laboratories Tailored optical interface for scintillation camera detector
US20050167605A1 (en) * 2003-11-20 2005-08-04 Juni Jack E. Edge effects treatment for crystals
DE102011085943A1 (en) * 2011-11-08 2013-05-08 Endress + Hauser Gmbh + Co. Kg Scintillation detector for radiometric measuring device, has retroreflection unit that is arranged in end of fiber bundle to perform retroreflection of incident light back to scintillation fiber bundles
CN101796428B (en) * 2007-09-07 2013-08-07 圣戈本陶瓷及塑料股份有限公司 Reduced edge effect detector
CN112951170A (en) * 2021-02-22 2021-06-11 京东方科技集团股份有限公司 Display control method and preparation method of display panel and display device

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2650420B2 (en) * 1989-06-09 1997-09-03 富士電機株式会社 Radioactive contamination measurement device
CN112269204B (en) * 2020-10-23 2022-11-18 中国工程物理研究院激光聚变研究中心 Microchannel type fast neutron flight time detector

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2695964A (en) * 1950-09-08 1954-11-30 Keleket X Ray Corp X-ray apparatus
US3073954A (en) * 1959-06-23 1963-01-15 Harshaw Chem Corp Shock resistant scintillation meter component
US3723735A (en) * 1971-02-01 1973-03-27 Nuclear Chicago Corp Radiation detecting apparatus
US3814938A (en) * 1972-07-10 1974-06-04 Picker Corp Scintillation camera with improved light diffusion
US4090081A (en) * 1975-07-28 1978-05-16 Hitachi Medical Corporation Scintillator for gamma ray camera

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3102955A (en) * 1960-07-06 1963-09-03 Harshaw Chem Corp Scintillation detector with compensating reflector for the crystal
US3683180A (en) * 1969-06-16 1972-08-08 Picker Corp Scintillation camera with removable subassembly
US3784819A (en) * 1971-03-05 1974-01-08 Picker Corp Scintillation camera with light diffusion system
FR2323158A1 (en) * 1974-01-10 1977-04-01 Radiologie Cie Gle HYBRID SCAN SCINTIGRAPHY UNIT

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2695964A (en) * 1950-09-08 1954-11-30 Keleket X Ray Corp X-ray apparatus
US3073954A (en) * 1959-06-23 1963-01-15 Harshaw Chem Corp Shock resistant scintillation meter component
US3723735A (en) * 1971-02-01 1973-03-27 Nuclear Chicago Corp Radiation detecting apparatus
US3814938A (en) * 1972-07-10 1974-06-04 Picker Corp Scintillation camera with improved light diffusion
US4090081A (en) * 1975-07-28 1978-05-16 Hitachi Medical Corporation Scintillator for gamma ray camera

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4492869A (en) * 1980-10-22 1985-01-08 Hitachi Medical Corporation Radiation detector
US4817123A (en) * 1984-09-21 1989-03-28 Picker International Digital radiography detector resolution improvement
US5229613A (en) * 1991-09-06 1993-07-20 Horiba Instruments, Incorporated Extended lifetime scintillation camera plate assembly
US5442181A (en) * 1991-10-03 1995-08-15 Kabushiki Kaisha Toshiba Radiation detector and its manufacturing method
US5442179A (en) * 1992-09-21 1995-08-15 Hamamatsu Photonics, K.K. Photomultiplier assembly and gamma camera head
US5550378A (en) * 1993-04-05 1996-08-27 Cardiac Mariners, Incorporated X-ray detector
WO1994029746A1 (en) * 1993-06-14 1994-12-22 Sloan-Kettering Institute For Cancer Research Radiation imaging device having an enlarged uniform field of view
US5763887A (en) * 1995-08-04 1998-06-09 Adac Laboratories Tailored optical interface for scintillation camera detector
US20050167605A1 (en) * 2003-11-20 2005-08-04 Juni Jack E. Edge effects treatment for crystals
US7138638B2 (en) 2003-11-20 2006-11-21 Juni Jack E Edge effects treatment for crystals
US20070096034A1 (en) * 2003-11-20 2007-05-03 Juni Jack E Edge effects treatment for crystals
CN101796428B (en) * 2007-09-07 2013-08-07 圣戈本陶瓷及塑料股份有限公司 Reduced edge effect detector
DE102011085943A1 (en) * 2011-11-08 2013-05-08 Endress + Hauser Gmbh + Co. Kg Scintillation detector for radiometric measuring device, has retroreflection unit that is arranged in end of fiber bundle to perform retroreflection of incident light back to scintillation fiber bundles
CN112951170A (en) * 2021-02-22 2021-06-11 京东方科技集团股份有限公司 Display control method and preparation method of display panel and display device

Also Published As

Publication number Publication date
JPS5578268A (en) 1980-06-12
EP0011902B1 (en) 1984-05-30
FR2443741B1 (en) 1981-10-16
JPS63101884U (en) 1988-07-02
DE2967025D1 (en) 1984-07-05
CA1134063A (en) 1982-10-19
JPH0134137Y2 (en) 1989-10-17
FR2443741A1 (en) 1980-07-04
EP0011902A1 (en) 1980-06-11

Similar Documents

Publication Publication Date Title
US4284891A (en) Gamma camera
Møller et al. Emission from a damped Ly-alpha absorber at z= 2.81
Brotherton et al. Discovery of radio-loud broad absorption line quasars using ultraviolet excess and deep radio selection
Osterbrock Seyfert galaxies with weak broad H alpha emission lines
Frei et al. Generating colors and K corrections from existing catalog data
Lawrence et al. MG 0414+ 0534: A dusty gravitational lens
US4109150A (en) Scintillation camera with the scintillators in different planes
Steidel et al. Discovery of an apparent companion galaxy to Q1548+ 0917 with Z= 2.758
Aoki et al. JHK imaging of the edge-on spiral galaxy NGC 891
Schmidt et al. A reinvestigation of the scattering halo of M82 based on polarimetric and isophotal maps
US3772507A (en) Visual display method and apparatus
Eales et al. The subarcsecond infrared structures at the centers of infrared-luminous galaxies
DE2746800C2 (en) Arrangement for receiving and reflecting light, in particular for shot simulation purposes
US6556284B1 (en) System for measuring the luminance characteristics of objects, in particular objects with luminance dependent on emitting direction
Keel Dust in backlit galaxies-Properties of the foreground systems in NGC 3314 and NGC 1275
US2954427A (en) Visual display system
US5302818A (en) Image detector with reduced parasitic light
US2490052A (en) Catoptric projection system for flying spot scanning
Perkins et al. The Red Rectangle: its polarization and structure
Vrba et al. JHKL photometry of three Herbig-Haro jet sources and a nebulous T Tauri star
KR940018064A (en) Radiation camera system
Santos et al. Two distant embedded clusters in the outer Galaxy
Forte et al. Dust within globular clusters
Netzer et al. Study of multiple nucleus galaxies. II-MKN 739
Neugebauer et al. High-spatial-resolution, near-infrared observations of ARP 220